FitnessU: 3 push-up circuits to work your arms, back, and core

Push-ups: That old school exercise we often take for granted. Push-ups work your arms, back, shoulders, core, and yes, even your legs; you can do them anywhere; and you’re guaranteed a great workout. To get the maximum benefit, master proper alignment and learn the variations and modifications.

Here, our trainer Frankie Romeo talks you through correct form and demos three push-up circuits—with beginner, intermediate, and advanced variations.